Contact roll assembly



1961 v. A. RAYBURN ,969,437

CONTACT ROLL ASSEMBLY Filed March 9, 1959 4 Sheets-Sheet 1 I J 1 VFW FFUK l Q Q Q) LL a J I a, m 255 m 9 2 9. m A M m l I s a"! It g INVENTORl/ A. RAVBURN ATTORNEY Jan. 24, 1961 v. A. RAYBURN CONTACT ROLL ASSEMBLY4 Sheets-Sheet 2 Filed March 9, 1959 INVENTOR 1 A. RAVBUR/V ATTORNEYJan. 24, 1961 v. A. RAYBURN CONTACT ROLL ASSE 'MBLY 4 Sheets-Sheet 3Filed March 9, 1959 INVENTORQ l/ A. PA YBUR/V ATTORNEY Jan. 24, 1961 v.A. RAYBURN 2,969,437

CONTACT ROLL ASSEMBLY Filed March 9, 1959 4 Sheets-Sheet 4 INVENTOR V.A. RA VBU/P/V A ORNEY CONTACT ROLL ASSEMBLY Vincent A. Rayburn,Baltimore, Md., assignor to Western Electric Company, Incorporated, NewYork, N.Y., a corporation of New York Filed Mar. 9, 1959, Ser. No.798,285

8 Claims. (Cl. 191-1) The present invention relates generally to contactroll assemblies, and more particularly to'an improved contact rollassembly of the internal brush type designed so that a stationary .brushbar carrying the brushes may be removed from within a rotary .outershell while the shell is rotating to facilitate replacement or cleaningof the brushes.

Various contact roll assemblies have been devised for use in thecontinuous electrotreating of advancing elongated material, wherein itis desired to apply an electrical charge to the material as it passesthrough a treating bath. Such assemblies are used, for example, in theelectroplating of a coating of a dissimilar metal on a plurality ofadvancing metallic wires, such as in the plating of copper and othermetals on steel wires in the communications industry.

A description of a general process for copper-cladding steel wire in thecommunications industry, in which the contact roll assembly of theinvention may be used, is to be found in anarticle entitled Developmentand Manufacture of Electroformed Conductor for Telephone Drop Wire, byA. N. Gray and G. E. Murray, appearing in The Bell System TechnicalJournal, vol. 32, pp. 1099- 1135, dated September 1953.

In such electroplating operations, the advancing wires pass aroundportions of the periphery of a series of rotary contact rolls, which arecathodically charged to conduct the plating current to the wires andwhich guide the wires through the plating baths. A suitable anode isdisposed in the plating bath to complete the circuit so as to enabledeposition of ametal coating from the electrolyte bath onto theadvancing wires.

According to certain prior arrangements, the contact roll assembly hasincluded a rotary cylindrical shell of conductive material around whichthe wires pass and a stationary brush bar of conductive material,extending axially into the shell and about which the shell isjournalled. The brush bar is connected to the negative terminal .of apotential source and functions to conduct'current to the shell. For thispurpose, a number of brushes are carried by the brush bar in electricalcontact therewith and in bearing contact with the inner surface of therotating shell at points near the points of contact between the wiresand the shell. The brush bar and shell are otherwise insulated from eachother and from .their surroundings.

In prior assemblies of this type, the brush bar has protruded from theshell on both sides thereof and has been secured to supporting memberson either side of the shell. A pair of annular endclosure members havebeen provided, which are secured to the inner surface of the shell andsurround the brush bar to seal ofi the assembly. In this instance,bearings are provided between the endclosure members and the brush barto permit rotation of the end-closure members and the shell, as a unit,about the stationary central brush bar.

Such an assembly functions well in operation; however, when the assemblymust be dismantled to replace 2,969,437 Patented Jan. 24, 1$6l .2 orclean the brushes, the dismantling operation is laborious and timeconsuming. In addition, the rotation of the shell must be stopped and anumber of threaded fasteners, such as bolts or the like, must be removedin order :to remove the end closures and the bearings to allowseparationof the brushbar from the shell so that work may be performed on thebrushes. In a continuous operation as described in 'the above-citedarticle, wherein twenty-five parallel wires advance at one-hungdred feetper :minute through a succession of .more than fifty separate cleaningand plating baths, it is extremely disadvantageous to stop thecontinuous advancement of the wires and shutdown the operation evenmomentarily.

For the foregoing reasons, it is highly desirable that a contact rollassembly be provided which will permit ready removal of the stationarybrush bar carrying the brush assembly from within the shell while theshell is rotating ,to permit rapid replacement or cleaning of thebrushes. It is also desirable to provide a contact roll assemblyarranged so that the entire assembly may be removed without interruptingthe advancement of the wires.

Accordingly, the general object of the present invention is to provide anew and improved contact roll assembly.

A more specific object of the invention is to provide a new and improvedcontact roll assembly of the internal brush type wherein a stationarybrush bar carrying the brushes may be removed from within a rotary outershell while the shell is rotating to permit rapid replacement orcleaning of the brushes.

A further object of the invention is to provide a contact rcll assemblywhich may be removed without interrupting the advancement of a number ofwires through an electroplating apparatus.

Another object of the invention is to provide 'aniimproved brushassembly wherein the brushes are slidably and insulatedly mounted in abrush bar and are electrically connected to the brush bar only through aconductor.

Yet another object of the invention is to provide bearings which areinsulated from the shell but which provide a path to ground for staticcharges.

An apparatus according to the invention, may include an improvement in acontact roll assembly having a rotary cylindrical shell, an electricallyconducting brush bar extending into the shell, and a brush extendingbetween the brush bar and the inner surface of the shell to conductcurrent from the brush bar to the shell. An improved assembly,illustrating certain features of the invention, may include a stationarycentering member extending into the shell from one end thereof anddesigned for supporting one end of the brush bar slidably thereon, andmeans for mounting the other end of the brush bar stationarily. Withthis arrangement, the brush bar may be removed from within the shellwhile theshell is rotating by disconnecting the mounting means andpulling the brush bar off of the centering member and out of the shell.

The brush bar and centering member may be provided with matingpin-and-socket ends permitting slidable reception of one end of thebrush bar on the centering member. Preferably, one end of the brush baris formed with a socket lined with an electrically insulating materialand the mating end of the centering member is formed with a projectingpin having a tapered nose for receiving the socket.

According to other features of the invention, a pair of opposed supportmembers are provided having aligned circular apertures therethrough forreceiving the shell and a pair of ball-bearing assemblies are mountedbetween the support members and the shell permitting rota- -biasing thebrushes into contact with the shell.

tion of the shell. The bearing assemblies include electricallyinsulating material on the shell sides thereof while providing a path toground on the support sides to permit static charges to leak off.Preferably, the shell is adjustable longitudinally in the bearings witha splined driving connection being used to permit such movement. Thebearing assembly may further be constructed to facilitate removal of theshell from the contact roll assembly without interrupting theadvancement of the wires.

According to still other features of the invention, an improved brushassembly may include a plurality of generally cylindrical brushesreceived slidably within a plurality of electrically insulated bores inthe brush bar, and a plurality of springs mounted within the boresllflor In t is arrangement, a plurality of flexible electricalconductors connect the brushes electrically with the brush bar.

Other objects and advantages of the invention will appear from thefollowing detailed description of a specific embodiment thereof, whenread in conjunction with the appended drawings, in which:

Fig. 1 is a fragmentary vertical section of a portion of anelectroplating apparatus including a plurality of cells and utilizingthe improved contact rolls of the invention;

Fig. 2 is a plan view of a portion of the apparatus illustrated in Fig.1, looking along the line 2-2, of Fig. 1

and illustrating the position of a contact roll with respect to adjacentplating cells;

Fig. 3 is an enlarged vertical section through an improved contact rollassembly according to the invention, taken generally along the line 3-3of Fig. 2 in the direction of the arrows and having portions broken awayto reveal structural details;

Fig. 4 is a fragmentary end view of the assembly illustrated in Fig. 3,looking from the right of Fig. 3 and illustrating details of a mountingmeans for a centering member;

Fig. 5 is a fragmentary end view looking from the left of Fig. 3 andillustrating details of a mounting means for a brush bar;

Fig. 6 is a fragmentary horizontal section with parts I removed forclarity, taken generally along the line 6-6 of Fig. 5 in the directionof the arrows and showing further details of the brush-bar mountingmeans, and

Fig. 7 is an enlarged vertical section, taken generally along the line7-7 of Fig. 3 in the direction of the arrows and illustrating details ofthe brush bar, the centering member, and a rotary shell.

Referring now in detail to the drawings and in particular to Figs. 1 and2, a plurality of cathodically charged contact rolls, designatedgenerally by the numerals 10- 10, are provided for advancing and guidinga number of parallel steel wires 11-11 through a series ofelectroplating cells 12-12 designed to deposit a continuous coating ofcopper onto the steel wires 11-11. The cells 12-12 may be of anysuitable construction, preferably as described in the Gray et al.article mentioned hereinbefore. Preferably, the cells 12-12 are arrangedin tandem and are alternately tilted in opposite directions as viewed inFig. l.

The contact rolls 10-10 are alternately disposed above and below theadvancing wires 11-11 and are so positioned that the wire-engagingportions of the bottoms of the upper rolls fall in a plane extendingbelow a plane defined by wire-engaging portions of the tops of the lowerrolls. With this arrangement, the wires 11-11 follow a zigzag path in avertical direction as they pass through the cells 12-12. Also, the wires11-11 contact the rolls 10-10 under tension over a definite arc alongthe periphery thereof to insure good electrical contact between thewires 11-11 and the rolls 10-10.

Referring now to Fig. 3, illustrating details of an improved contactroll assembly 10 according to the principles of this invention, theassembly 10 includes a rotary, cylindrical shell 13 around which wires11-11 advance in tight contact therewith over an are on the peripherythereof. The shell 13 is made of a material which is both resistant tocorrosion due to the electrolyte carried by the wires 11-11 and which isat least a fair conductor of electricity, such as stainless steel orMonel metal.

The shell 13 is journalled at either end in a pair of bearingassemblies, designated generally by the numerals 14-14, for rotationwithin a pair of aligned circular apertures 15-15 formed in an opposedpair of main support members or brackets 16-16. The two brackets 16-16are identical but positionally reversed, being shown in elevation inFigs. 4 and 5 with the bracket 16 at the left in Fig. 3 being shown inhorizontal section in Fig. 6. A trough having side walls 17-17 shown inFig. 3, a bottom 18 shown in Fig. l, and an inner lining 19 ofcorrosion-resistant material, such as Koroseal, is secured to theopposing support brackets 16-16.

A pair of annular retaining caps 22-22 of Koroseal or the like having agenerally U-shaped cross section are fitted within aligned apertures inthe trough walls 17-17 and have portions which extend radially outwardlyof the apertures around the walls, and a pair of generally ring-shapedshield members 23-23 made of soft rubber or a similar material arefitted within the retaining caps 22-22 and each have portions thereofwhich extend radially outwardly of the associated cap 22 on both sidesthereof, as illustrated in Fig. 3. The ends of the shell 13 are formedwith reduced diameter portions 24-24 around which are received inrubber-band fashion a pair of slinger rings or splash-containing members26-26, which cooperate with the shields 23-23 to form a seal, designatedgenerally by the numeral 27, at each end of the shell 13 preventingseepage of the electrolyte or fumes through the trough walls 17-17 tothe bearing assemblies 14-14.

The shell 13 is rotatably driven in any desired synchronism with thespeed of advancement of the wires 11-11 by a suitable motor 28 whichdrives a sprocket wheel, designated generally by the numeral 29, througha chain 31. The sprocket wheel 29 includes an externally splined hub 32,which projects coaxially a short distance into an axial bore 33 of theshell 13 from the right as viewed in Fig. 3. The externally splined hub32 meshes with an internally splined ring 34, which is secured within acounterbore 36 at the end of the shell 13 by means of a key 37 and amachine screw 38. The splined ring 34 is made of Micarta or otherstrong, electrically insulating material to prevent conduction ofcurrent from the shell 13 to the sprocket wheel 29. It should be notedthat the left end of the shell 13 is provided with an identicalcounterbore 36, which permits driving of the shell 13 from either endthereof.

With the arrangement described, any rotation imparted to the sprocketwheel 29 by the motor 28 is transmitted to the shell 13 through thesplined hub 32 and the splined ring 34. The meshing splines on the hub32 and ring 34 allow longitudinal shifting of the position of the shell13 and the ring 34 secured thereto with respect to the trough walls17-17 and the sprocket wheel 29. The shell 13 is illustrated in itsextreme leftward position in Fig. 3, but it can be seen that the shell13 may be moved longitudinally a distance to the right almost equal tothe spacing between adjacent parallel wires 11-11 while maintaining thesplined driving connection between the hub 32 and the ring 34.

The purpose of the longitudinal shifting movement of the shell 13 is topermit precise alignment of a plurality of Wire-carrying grooves 39-39formed around the periphery of the shell 13 with similar grooves 39-39formed around all of the other contact rolls 10-10 shown in Fig. 1. Inaddition, as many as three extra sets of grooves (not shown) may be outbetween the Lgrooves39-39 shownin Figs. 2 and 3 Si tg Whenrone set ofgrooves becomes worn, the shell -13may be shifted to bring a new set ofthegrooves into operation. "When the position of the shell 13 is to beshifted, the slinger rings 26-26 are maintained substantially in place-while the shell 13 is slid therepast. For this purpose, a greasedspatula-like instrument is inserted between the shell -1-3 and the rings26-26 to permit the sliding movement. The limit of thisslidingmovement-is defined bytheleft edge of the reduced diameterportion24 of the shell 13 at the right of Fig. 3.

In-practice, the contact rolls 10-10 may be so driven that theperipheral speed thereof is substantially equal to the speed ofadvancement of the wires 11'- 11 to minimize frictional contact betweenthe wires and the .shells 13-13, or the rolls maybe overdriven bypreselected amounts to assist in carrying the wires 11-11 through theseries .of cells 12-12. Preferably, each roll is driven both faster thanthe wire and slightly faster than the previous roll 10.

Considering now the construction of one of the hearing assemblies 14-14,the inner race 41 of a conventional ball-bearing unit, designatedgenerally by the numeral 42, is bonded to the outer periphery of aninsulating ring 43 of suitable material, such asan epoxy .resin. Ametallic sleeve 44 is bonded to the inner periphery of the insulatingring 43, and thesleeve .44 is secured around the shell 13 .-for rotationtherewith by means of a plurality of set screws 46-46. When it isdesired to adjust the longitudinal position of the shell 13, the setscrews 46-46 are merely loosened to .allow sliding movement of the shell13 within the normally loose-fitting sleeve 44. The insulating ring 43prevents passage of current from the shell 13 to .the ball-bearing unit42.

Each of the outer races 47-47 of the hall-bearing units 42-42 is securedto the adjacent support bracket 16'by means of an inner housing 48, anouter retaining ring 49, and a plurality of cap screws 51-51 passingthrough the members 48 and 49 and threadedly received in the bracket 16.One important feature of this assembly is that,. although the inner race41 .of the bearing unit 42 is insulated from the rotating,current-carrying shell '13, the outer race 47 is connected to groundthrough the metallic mounting members 48 and 49 so that any staticcharges built up in the bearing unit 42 aregrounded oft" harmlessly.

Another advantage of the particular bearing assembly 14 provided is thatthe shell 13 may easily be removed from the support brackets 16-16 toallow replacement thereof when the grooves 39-39 are worn or when it isotherwise desired to perform work on the shell 13. Removal of the shell13 may be accomplished, as viewed in Fig. 3, by stopping the motor 28 orotherwise 'disconnecting the sprocket wheel 29 from the drive motor 28as by lifting the chain 31 off of the sprocket wheel 29. Then, the setscrews 46-46 at the right of the contact roll 10 are loosened to permitsliding movement of the shell 13 and the internally splined ring 34 outof contact with the Sleeve 44 of the bearing unit 14 and the externallysplined hub 32 of the sprocket wheel 29.

The bearing assembly 14 at the left of Fig. 3 is then dismantled. Beforethis may be done, a composite brush-bar mounting plate, designatedgenerally by the numeral 52 and to be described in detail hereinafter,must be removed. Then, the set screws 46-46 at the left of Fig. 3 areloosened and the cap screws 51-51 are removed. Next, the retaining ring49, the innerrace assembly including the ring 43 and the bearing unit 42bonded thereto, and the inner housing 48 are pulled 0E of the shell 13and away from the support bracket 16.

The shell 13 is then pulled out of the supporting assembly, fromn'ght-to-left as viewed in Fig. 3, with the outwardly projectingportions of the soft-rubber slinger rings 26-26 being deformedsufliciently .to pass y .the vsOft-rubberi-shield .23. The same shell 13or a replacement therefor may :readily be reassembled by repeating thedismounting steps in reverse. When a shell 13 is beingremoved,.there.-is no need to stopthe advancement of the wires 11-11with the alternate over-andunder roll construction illustrated in Fig.1, since the remaining rolls 10-10 will be suflicienttosupportthe wires11-11.

The plating current is conducted to the shell 13 by means of arectangular, generally solid brush bar, designated generally by thenumeral 53 and best-seen in Figs. 3 and 7. The 'brush bar 53 is made ofelectrically conductive material, such as copper. The brush bar 53 isstationarily mounted by means of the mounting plate 52 and is looselyreceived within the central bore 33 inthe shell 13, as illustrated inFig. 7, extending over themajor portion of the length thereof, asillustrated in Fig. 3. The brush bar 53 is supported within the shell 13near the right end thereof on a centering member designatedgenerallybythe numeral 5.4. The centering member 54 extends axially intotheshell 13 from the right-end thereof and is designed for supportingvthe right end of the brush ,bar53'slidably thereon, so thatthe brushbar 53 is pre- .cisely centered axially within the shell 13.

The centering member 54 includes a cylindrical shaft .56, .a circular.flange57 {formed therearound, and a pin 58 which projects from theflange 57 to the left as viewed in Fig. 3 and has atapered nose portion59. The centering member is secured by means of a nut 61 to a mounting,plate designated .generally by the numeral 62. As illustrated in Fig.4, the mounting plate 62 is in turn secured ateitherend by meansof anumber of cap screws 63-63 to ,a pair of projecting webportions 6464 ofthe right- .end support bracket 16. The nut 61 is received in a recess'66 in the mounting plate 62 and is threadedly received within a tappedaperture67 in the shaft 56.

The mounting plate 62 also includes an inwardly projecting hub68, whichis axially bored for slidable reception over the shaft 56 up tostoppingengagement with the flange 57. An inner bearing assembly, designatedgenerally by the numeral 69 and including a spacer sleeve 71,ispositioned between the outer periphery of the stationary .hub 68 ofthe mounting plate 62 and the inner periphery of the rotating geared hub32 of the sprocket wheel 29 to permit rotation of thesprocket wheel 29about the 'hub 68 and thus rotation of the shell 13 about the stationarybrush bar 53.

As'best seen in Figs. 3 and 7, the projecting pin 58 of the centeringmember 54 is designed to receive slidably thereon acircular socket 72formed in the right-hand or inner end of the brush bar 53. The socket 72is defined by a bore in an insulating bushing 73 of suitable'materialsuch as nylon, whichis mounted within a projecting circjular sleeve 74welded to the end of the brush bar 53. Theinsulating bushing 73 preventsthe conduction of currentfrom the brush bar 53 to the centering member54 and thus to the mounting plate 62 or the inner bearing assembly 69.

With this mating pin-and-socket construction, it will be apparent thatthe inner end of the brush bar 53 is supported on the stationarycentering member 54 coaxially within the rotary shell '13 duringoperation, but that the brush bar 53 may readily be pulled off of thestationary centering member 54, from left to right as viewed in Fig. 3,when it is desired to remove the brush bar 53 from within the shell 13.The same or another brush bar 53 may later be inserted into operatingposition by merely sliding the brush bar 53 back into the shell 13 untilthe socket 72 passes over the pin 58, the tapered nose 59 facilitatingthe inserting step. I

It should be understood that the exemplary construction illustrated inFigs. 3 and 7, with a locating pin 58 .provided at the end of thecentering member 54 and an insulated socket 72formed at the end of thebrush bar 53, is only .a preferred arrangement for supporting the innerend of the brush bar 53 slidably and coaxially'within the rotary shell13 but out of contact therewith for ready removal therefrom. It will beobvious that the brush bar 53 might have been formed with a terminal pinor pins and the centering member 54 witha socket or sockets toaccomplish the same result, and that other arrangements might be devisedpermitting slidable reception of the brush bar 53 on the centeringmember 54 for the purposes of the invention.

In any event, the brush bar 53 is made of sufficient length so that theleft-hand or outer end thereof projects a short distance out of theshell 13 when the bar 53 is in operating position supported on thecentering member 54, as illustrated in Figs. 3 and 6. The outer end ofthe brush bar 53 is secured by means of a pair of cap screws 75-75 tothe composite brush-bar mounting plate 52, previously mentioned ingeneral as being required to be removed before the shell 13 can bedismounted.

As best seen in Fig. 5, the composite plate 52 is provided with agenerally T-shaped central section 76 of electrically conductivematerial such as copper, which operates as a brush-bar feeder to conductthe plating current from a laminated, flexible negative bus bar 77 tothe brush bar 53. The conductive central section is mounted near the topthereof by the cap screws 75-75 to the brush bar 53 and is mounted nearthe bottom thereof by four cap screws 78-78 to the bus bar 77.

The central section 76 is bonded by means of a pair of insulating layers79-79 of an epoxy resin or similar material on either side thereof to apair of end sections 81-81 of the composite mounting plate 52, as bestseen in Figs. and 6. The end sections 81-81 are fastened by means of aplurality of cap screws 8282 to a pair of projecting web portions 83-83of the left-end support bracket 16. It should be noted that theconnection of the plate 52 to the webs 83-83, as illustrated in Fig. 6,is substantially identical with the connection of the mounting plate 52to the webs 64-64 of the right-hand support bracket 16, describedhereinbefore. The composite mounting plate 52 permits current to travelfrom the bus bar 77 through the central section 76 to the brush bar 53,while preventing the passage of current to the end sections 81-81 andthe support bracket 16 because of the intermediate insulating layers79-79.

Referring again to Figs. 3 and 7, the plating current is conducted fromthe stationary brush bar 53 to the rotating shell 13 by means of aplurality of generally cylindrical, copper-graphite brushes 84-84carried by the rod 53 in electrical contact therewith and engaging theinner surface of the shell 13, which is highly polished to reducefriction, in the vicinity of each wire-carrying groove 39 along theouter surface thereof. With this arrangement, a relatively shortconducting path is provided through the stainless steel shell 13 betweenthe brushes 84-84 and the wires 11-11 to minimize the resistive effectsof the steel, the length of the path being limited only by the thicknessof the shell 13 required for strength.

The shell 13 could be made of a more conductive material such as copper,in a situation where the electrolyte carried by the wires 11-11 isnoncorrosive to copper; however, a material must be selected which isnot corroded substantially by the electrolyte and which is at least afair conductor of electricity. For some applications, the shell maycomprise an inner shell of copper with a thin sleeve of a more corrosionresistant metal such as steel secured therearound, but deleteriouselectrical eifects may be encountered at the juncture line between thecopper and the steel.

Each of the individual brushes 8484 is a part of a brush assembly,designated generally by the numeral 86, one of which is illustrated indetail in Fig. 3. The brush assembly 86 is carried within a bore 87drilled through the bar 53 from top to bottom, as viewed in Fig. 3.

A nylon sleeve 88 is secured within the bore 87 and the brush 84 isslidably received therein. The nylon material of the sleeve 88 functionsboth to insulate the brush 84 from direct electrical contact with thebrush bar 53 and to minimize friction between the brush 84 and thesleeve 88, thus facilitating sliding movement of the brush 84. Othermaterials than nylon might be employed for the sleeve 88, provided theyare good electrical insulators and are also relatively frictionless tosliding movement of the brush 84, having regard to the particularmaterial of which the brush is made.

The brush 84 is biased upwardly with respect to the brush bar 53 intobearing engagement with the inner periphery of the shell 13 by means ofa coil spring 89 positioned within the bore 87 and supported on anadjustable threaded plug 91 of insulating material such as polyvinylchloride. Electrical connection is made between the brush 84 and thebrush bar 53 by means of a flexible pigtail conductor 92, which isconnected at one end to the brush 84 and which assumes the U-shapeillustrated in Fig. 3. The other end of the conductor 92 is providedwith a plug 93, which is received in a socket 94 formed in the undersurface of the brush bar 53.

The mounting of the brushes 84-84 out of direct electrical contact withthe brush bar 53 by means of the insulating sleeves 88-88 permitscurrent to flow to the brushes 84-84 only through the plugs 91-91 andthe conductors 92-92, thus providing substantially equal potentials atthe several points of contact between the wires 11-11 and the shell 13.

It will be understood that the roll 10 particularly illustrated in Fig.3 is one of the lower rolls 10-10 illustrated in Fig. 1, over which thewires 11-11 advance. The upper rolls 10-10 under which the wires 11-11advance are constructed exactly the same, except that the brush bar 53is mounted upside down with respect to the mounting illustrated in Fig.3, with the brushes 84-84 extending downwardly from the bar 53 intobearing contact with the lower, inner surface of the shell 13. For thisreason, the cap screws 75-75 are made of different sizes so that thebrush bar 53 may not be inserted in any unit 10 in incorrectly orientedposition.

When the brushes 84-84 have become worn or are otherwise ineffective toconduct the desired current to the advancing wires 11-11, the brush bar53 may be removed from within the rotating shell 13 without interruptingthe rotation thereof. This is accomplished simply and conveniently byfirst disconnecting the current to the negative bus bar 77; second,unfastening the cap screws 78-78 and 82-82 (Fig. 5) which secure themounting plate 52 to the brush bar 53 and the support bracket 16,respectively; third, lowering the plate 52 away from the brush bar 53,which motion is permitted by the provision of the flexible bus bar 77;and, finally, pulling the brush bar 53 ofi of the centering member 54and out of the rotating shell 13, from left to right as viewed in Fig.1.

When the brush bar 53 has been removed, the brushes 84-84 may becleaned, replaced, or otherwise operated upon. Later, the same or areplacement bar 53 may be reinserted into the rotating shell byreversing the dismounting steps just described. When a brush bar 53 or ashell 13 is being removed, with the power supply disconnected from oneof the cells 12-12, the current applied to the remaining cells 12-12 inthe series is automatically stepped up by that amount necessary tocounterbalance the efiect of losing one cell in order to provide forcontinuous plating even though one cell has been disconnected.

It will be obvious that this invention is not limited to the specificdetails described in connection with the above embodiment of theinvention, but that various modifications may be made without departingfrom the spirit and scope thereof.

What is claimed is:

1. In a contact roll assembly having a rotary cylindrical shell, anelectrically conducting brush bar extending into the shell, and a brushextending between the brush bar and the inner surface of the shell toconduct current from the brush bar to the shell; the improvement whichcomprises a stationary centering member extending into the shell fromone end thereof and designed for supporting one end of the brush barslidably thereon, and means for mounting the other end of the brush barstationarily, whereby the brush bar may be removed from within the shellwhile the shell is rotating by disconnecting said mounting means andpulling the brush bar off of said centering member and out of'theshell..

2. In a contact roll assembly having a rotary cylindrical shell ofelectrically conductive material which contacts an advancing wire, anelectrically conducting brush bar extending into the shell and a brushcarried by the brush bar in electrical, contact therewith and engagingthe inner surface of the shell to conduct current from the brush barthrough the shell to the advancing wire; the improvement which comprisesa stationary centering member extending into thev shell from one endthereof, the brush bar and centering member being pro vided with matingpin-and-socket ends permitting slidable reception of one end of thebrush bar on said centering member with the brush bar centered axiallywithin the shell, bearing means permitting rotation of the shell aboutsaid centering member, and means for mounting the other end of the brushbar stationarily, whereby the brush bar may be removed from within theshell while the shell is rotating by disconnecting said mounting meansand pulling the brush bar off of said centering member and out of theshell.

3. In a contact roll assembly having a rotary cylindrical shell ofelectrically conductive material which contacts a plurality of advancingparallel wires, an electrically conducting brush bar extending axiallyinto the shell and a plurality of brushes carried by the brush bar inelectrical contact therewith and engaging the inner surface of the shellnear the points of contact between the wires and the shell to conductcurrent from the brush bar through the shell to the advancing wires; theimprovement which comprises a pair of opposed support members, acentering member including a generally cylindrical pin projectingtherefrom and having a tapered nose, means for securing said centeringmember to one of said support members so that the pin projects axiallyinto the shell from one end thereof, one end of the brush bar beingformed with a socket therein lined with an electrically insulatingmaterial and designed for slidable reception over the pin of saidcentering member in order to support one end of the brush bar axiallywithin the shell, bearing means permitting rotation of the shell aboutsaid centering member and the securing means therefor, and means forsecuring the other end of the brush bar to the other support member,whereby the brush bar is mounted stationarily and coaxially Within theshell out of contact therewith and may be removed from within the shellwhile the shell is rotating by unfastening the lastrnentioned securingmeans and pulling the brush bar off of said centering member and out ofthe shell.

4. In a contact roll assembly having a rotary cylindrical shell ofelectrically conductive material which contacts an advancing wire, anelectrically conducting brush bar mounted stationarily and extendinginto the shell and a brush extending between the brush bar and the innersurface of the shell to conduct current from the brush bar to the shell;the improvement which comprises a pair of opposed support members havingaligned circular apertures therethrough, the shell being mounted betweensaid support members so that the ends of the shell extend through thealigned apertures, and a pair of ball-bearing assemblies mounted betweensaid support members and the shell for permitting rotation of the shellwith respect to said support members, said ball-bearing assembliesincluding electrically insulating material on the shell sides thereof toinsulate the bearings-from: the shellbut. including electricallyconductive paths to ground on the: support sides thereof to dischargeany static chargeszaccumulated thereby to ground.

5. In a contact roll assembly having a rotatable cylindrical shell'ofelectrically conductive materi'al'whichcontacts an advancing wire,an-electrically-conducting brush barmounted stationarily andextendingaxially into the shell, and a brush extendingbetween the brush bar andthe inner surface of the shell to conductcurrent from the brush bar tothe shell; the improvement which comprises a pair of opposed supportmembers having: aligned circular apertures therethrough, the shell beingmounted between said support members so that the ends of the-shellextend through the aligned apertures, a pair of ball-bearing unitsincluding inner and outer bearing-races mounted between said supportmembers and the ends of the shell for permitting rotation of the shellwith respect to said support members,,a pair of metallic sleeves havinginner diameters slightly greater than the outer diameter of the shellfor slidable reception thereover, a pair of rings of an electricallyinsulating material bonded between the innerbearing races and saidsleeves, a plurality of set screws for securing saidsleeves to theouter'surface of the shell for rotation therewith, and drivingconnection means including a pair of splined gears at least one of whichis made of electrically insulating material for rotating said shell fromone end thereof, whereby the longitudinal position of the shell may beshifted by loosening said set screws and sliding the shell within saidsleeves with the splined gears designed for retaining the drivingconnection for the shell.

6. The apparatus defined in claim 5 which comprises, in addition, a pairof bearing housings fitting against said support members and receivingportions of the outer races of said ball-bearing units, a pair ofretaining rings fitting against said housings and receiving otherportions of the outer races of said ball-bearing units, and a pluralityof screws for securing said housings and said retaining rings to saidsupports, whereby the contact roll assembly may readily be dismantled byremoving the driving connection for the shell, removing the brush barfrom within the shell, loosening the set screws at the driving end ofthe shell, removing the bearing assembly at the other end of the shell,and then pulling the shell out of the contact roll assembly.

7. In a contact roll assembly having a rotary cylindrical shell ofelectrically conductive material which contacts an advancing wire, anelectrically conducting brush bar mounted stationarily and extendingaxially into the shell and a brush extending between the brush bar andthe inner surface of the shell to conduct current from the brush bar tothe shell; the improvement which comprises a pair of opposed supportmembers having aligned circular apertures therethrough, the shell beingmounted between said support members so that the ends of the shellextend through the aligned apertures, a pair of ballbearing assembliesmounted between said support members and the ends of the shell forpermitting rotation of the shell with respect to said support members,said ballbearing assemblies including electrically insulating materialon the shell sides thereof to insulate the bearings from the shell butincluding electrically conductive paths to ground on the support sidesthereof to discharge any static charges accumulated thereby to ground, acentering member, means for securing said centering member to one ofsaid support members so that said centering member extends axially intothe shell, the brush bar and centering member being provided with matingpin-and socket ends permitting slidable reception of one end of thebrush bar on said centering member with the brush bar centered axiallywithin the shell, bearing means permitting rotation of the shell aboutsaid centering member, and means for securing the other end of the brushbar to the other support member.

8. A contact roll assembly, which comprises a pair of opposed supportmembers having aligned circular apertures therethrough, arotatablecylindrical shell of electrically conductive material mounted betweensaid support members so that the ends of the shell extend through thealigned apertures, 'a pair of bearing units including inner and outerbearing races mounted between said support members and the ends of theshell for permitting rotation of the shell with respect to the supportmembers, a pair of bearing housings fitting against said support membersand receiving portions of the outer races of said bearing units, saidhousings forming electrically conductive paths to ground on the supportsides of the bearing units to discharge any static charges accumulatedthereby to ground, means including a pair of splined gears for rotatingsaid shell from one end thereof, one of said gears being made ofelectrically insulating material, a centering member including agenerally cylindrical pin projecting therefrom and having a taperednose, means for securing said centering member to one of said supportmembers through said splined gears, said shell and one of said bearingunits so that said pin projects axially into the shell, bearing meanspermitting rotation of the shell about said centering member, a brushbar having a plurality of bores formed therein transversely thereof, oneend of the brush bar being formed with a socket therein lined with anelectrically insulating material and designed for slidable receptionover the pinof the centering member to support one end of the brush baraxially in the shell, means for securing the other end of the brush barstationarily to the other support member, insulating sleeves in thebores in the brush bar, a plurality of brushes of electricallyconductive material received slidably within the insulating sleeves inthe bores in the brush bar, means for biasing said brushes outwardlywith respect to the brush bar into contact with the internal surface ofsaid shell, and a plurality of flexible electrical conductors forconnecting said brushes electrically to said brush bar.

References Cited in the file of this patent UNITED STATES PATENTS846,778 Christman Mar. 12, 1907 913,432 Rew Feb. 23, 1909 1,970,604 rHenry Aug. 21, 1934 2,446,548 Nachtman Aug. 10, 1948 2,643,303 FrankwichJune 23, 1953

